Coatings containing silicone mist suppressant compositions

ABSTRACT

This invention relates to silicone coating composition comprising a solventless silicone coating composition and a liquid silicone mist suppressant composition obtained by a method comprising reacting at least one organohydrogensilicon compound containing at least two silicon-bonded hydrogen groups with a large excess of at least one organoalkenylsiloxane containing at least three silicon-bonded alkenyl groups in the presence of a platinum group metal-containing catalyst.

BACKGROUND OF THE INVENTION

During the process of coating silicone on to paper for release coatingapplications, the formation of silicone mist (i.e. aerosol) isundesirable. Small mist particles, on the order of 1 to 10 microns areconsidered to be capable of being inhaled and can be deposited deepwithin the lungs. Silicone mist can also cause hygiene problems bycoating everything in the vicinity of the coating head with a layer ofsilicone.

Solventless silicone coatings have been disclosed in the art. Forexample, Chung et al. in U.S. Pat. No. 5,036,117 discloses a curablecomposition comprising (A) an organosilicon compound having an averageof at least two curing radicals per molecule thereof selected from thegroup consisting of the hydroxy radical and olefinic hydrocarbonradicals, (B) an organohydrogensilicon compound containing an average ofat least two silicon-bonded hydrogen atoms per molecule thereof, theamounts of Components (A) and (B) being sufficient to provide a ratio ofthe number of silicon-bonded hydrogen atoms to the number ofsilicon-bonded curing radicals of from 1/100 to 100/1, (C) a platinumgroup metal-containing catalyst in sufficient amount to accelerate acuring reaction among said silicon-bonded curing radicals and saidsilicon-bonded hydrogen atoms, (D) an inhibitor compound for saidaccelerated curing reaction in a total amount sufficient to retard thecuring reaction at room temperature but insufficient to prevent saidreaction at elevated temperature, and (E) a bath life extender compoundin a total amount sufficient to further retard the curing reaction atroom temperature.

Jones et al. in U.S. Pat. No. 5,125,998 discloses a process, the processcomprising the steps of (I) first mixing (A) an inhibitor compound and(B) a platinum group metal-containing catalyst, (II) thereafter addingthe mixture of (I) to (C) an organosilicon compound having an average ofat least two curing radicals per molecule thereof selected from thegroup consisting of the hydroxy radical and olefinic hydrocarbonradicals, (III) thereafter adding to the mixture of (II) (D) anorganohydrogensilicon compound containing an average of at least twosilicon-bonded hydrogen atoms per molecule thereof, the amounts ofcomponents (C) and (D) being sufficient to provide a ratio of the numberof silicon-bonded hydrogen atoms to the number of silicon-bonded curingradicals of from 1/100 to 100/1; (IV) applying the mixture from (II) toa solid substrate to form a coating; (V) exposing the coating to anenergy source selected from the group consisting of (i) heat, and (ii)actinic radiation in an amount sufficient to cure the coating; wherebythe amount of component (A) present in the total composition ofcomponents (A), (B), (C), and (D), is sufficient to retard any curingreaction at room temperature but insufficient to prevent any reaction atelevated temperatures; and whereby the amount of component (B) issufficient to accelerate any curing reaction among the silicon-bondedcuring radicals and the silicon-bonded hydrogen atoms at elevatedtemperatures.

Thayer et al. in U.S. Pat. No. 5,281,656 discloses coating compositionscomprising (A) an alkenyldiorganosiloxy-terminated polydiorganosiloxane,(B) an alkenyldiorganosiloxy-terminatedpolydiorganosiloxane-polyorganoalkenylsiloxane copolymer, (C) ahydrogendiorganosiloxy-terminated polydiorganosiloxane, (D) aplatinum-containing catalyst, and (D) an inhibitor. Thayer et al.further discloses the amounts of Components (A), (B) and (C) that areused in the compositions, expressed in terms of the ratio of the numberof silicon-bonded hydrogen atoms of Component (C) to the number ofsilicon-bonded alkenyl radicals of Components (A) and (B), aresufficient to provide a value of from 1/2 to 20/1 for said ratio and,preferably, from 1/2 to 2/1, and even more preferably, about 1/1.

Silicone compositions which are useful in suppressing silicone mist havealso been described in the art. For example, Chung et al. in U.S. Pat.No. 5,625,023 discloses silicone mist suppressant compositions which areprepared by reacting an organosilicon compound, an oxyalkylenecontaining compound, and a catalyst. Chung et al. further discloses thatthese compositions, when added to silicone coatings, reduce the amountof silicone mist in high speed coating processes. These silicone mistsuppressant compositions were only partially compatible with siliconeand produced a cloudy mixture when added to coating formulations. Thispartial incompatibility was believed to be critical to themist-suppression performance of these materials. However, the use ofthese suppressant also introduced new issues with the coverage andanchorage of the silicone release coating.

SUMMARY OF THE INVENTION

This invention relates to silicone coating composition comprising asolventless silicone coating composition and a liquid silicone mistsuppressant composition obtained by a method comprising reacting atleast one organohydrogensilicon compound containing at least twosilicon-bonded hydrogen groups with a large excess of at least oneorganoalkenylsiloxane containing at least three silicon-bonded alkenylgroups in the presence of a platinum group metal-containing catalyst.

This invention also relates to a method of reducing mist in asolventless silicone coating which comprises adding to a solventlesssilicone coating a liquid silicone mist suppressant composition obtainedby a method comprising reacting at least one organohydrogensiliconcompound containing at least two silicon-bonded hydrogen groups with alarge excess of at least one organoalkenylsiloxane containing at leastthree silicon-bonded alkenyl groups in the presence of a platinum groupmetal-containing catalyst.

The present invention also relates to the use of the siliconesuppressant compositions in processes for preparing a laminate of asubstrate and an adhesive wherein the adhesive will release from thesubstrate.

It is an object of this invention to provide a silicone compositionwhich is capable of mist suppression in silicone coatings employed inhigh speed coating processes.

DETAILED DESCRIPTION OF THE INVENTION

In a first embodiment, this invention relates to a silcone coatingcomposition comprising (A) a solventless silicone coating compositionand (B) a liquid silicone mist suppressant composition having aviscosity of from 150 to 50,000 millipascal-seconds (mPa·s) (1millipascal-second=1 centipoise) obtained by a method comprising mixing:(a) at least one organohydrogensilicon compound containing at least twosilicon-bonded hydrogen groups per molecule, (b) at least oneorganoalkenylsiloxane containing at least three silicon-bonded alkenylgroups per molecule, and (c) a platinum group metal-containing catalystwhich is present in an amount sufficient to provide 1 to 250 weightparts of platinum group metal per million weight parts of (a)+(b), withthe proviso that the ratio of the number of silicon-bonded hydrogenatoms of Component (a) to the number of silicon-bonded alkenyl groups ofComponent (b) is less than or equal to 1:4.6.

Component (A), the solventless silicone coating can be any of thewell-known solventless hydrosilylation reaction based compositions knownin the art. These solventless silicone coating compositions typicallycomprise (i) an organosilicon compound containing at least twosilicon-bonded alkenyl groups per molecule, (ii) anorganohydrogensilicon compound containing at least two silicon-bondedhydrogen atoms per molecule, (iii) a platinum group metal-containingcatalyst, and (iv) an inhibitor.

The alkenyl groups of Component (i) are exemplified by vinyl, allyl,3-butenyl, 4-pentenyl, 5-hexenyl, 6-heptenyl, 7-octenyl, 8-nonenyl,9-decenyl, 10-undecenyl, 4,7-octadienyl, 5,8-nonadienyl, 5,9-decadienyl,6,11-dodecadienyl and 4,8-nonadienyl.

Component (i) is exemplified by triorganosiloxy-terminatedpolydiorganosiloxane-polyorganoalkenylsiloxane copolymers,alkenyldiorganosiloxy-terminatedpolydiorganosiloxane-polyorganoalkenylsiloxane copolymers,triorganosiloxy-terminatedpolydiorganosiloxane-polyorganoalkenylsiloxane copolymers,alkenyldiorganosiloxy-terminatedpolydiorganosiloxane-polyorganoalkenylsiloxane copolymers,triorganosiloxy-terminated polyorganoalkenylsiloxane polymers, andalkenyldiorganosiloxy-terminated polydiorganosiloxane polymers, eachhaving a degree of polymerization of from 20 to 500, preferably from 50to 300 and a viscosity at 25° C. of from 50 to 2,000millipascal-seconds, and preferably from 80 to 1,000millipascal-seconds. The organo substituent is exemplified by amonovalent hydrocarbon group having from 1 to 20 carbon atomsexemplified by alkyl groups such as methyl, ethyl, propyl, butyl, hexyl,octyl, and decyl, cycloaliphatic groups such as cyclohexyl, aryl groupssuch as phenyl, tolyl, and xylyl, and aralkyl groups such as benzyl andphenylethyl. It is preferred that the organo substituent is methyl. Theseveral organo substituents can be identical or different, as desired.The alkenyl substituent is exemplified by vinyl, allyl, 3-butenyl,4-pentenyl, 5-hexenyl, cyclohexenyl, 6-heptenyl, 7-octenyl, 8-nonenyl,9-decenyl, 10-undecenyl, 4,7-octadienyl, 5,8-nonadienyl, 5,9-decadienyl,6,11-dodecadienyl, and 4,8-nonadienyl, with vinyl and 5-hexenyl beingpreferred.

Component (i) is preferably selected from the group consisting oftrimethylsiloxy-terminated polydimethylsiloxane-polymethylvinylsiloxanecopolymers, vinyldimethylsiloxy-terminatedpolydimethylsiloxane-polymethylvinylsiloxane copolymers,trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhexenylsiloxane copolymers,hexenyldimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhexenylsiloxanec coplymers,trimethylsiloxy-terminated polymethylvinylsiloxane polymers,trimethylsiloxy-terminated polymethylhexenylsiloxane polymers,vinyldimethylsiloxy-terminated polydimethylsiloxane polymers, andhexenyldimethylsiloxy-terminated polydimethylsiloxane polymers, eachhaving a degree of polymerization of from 50 to 300 and a viscosity at25° C. of from 80 to 1,000 millipascal-seconds. Component (i) can alsobe a combination of two or more of the above described alkenylsiloxanes.

The organohydrogensilicon compound of Component (ii) is preferably freeof aliphatic unsaturation and contains two, three, or more silicon atomslinked by divalent radicals, an average of from one to twosilicon-bonded monovalent radicals per silicon atom and an average of atleast two or more silicon-bonded hydrogen atoms per compound. Theorganohydrogensilicon compound is preferably an organohydrogensiloxanecontaining an average of three or more silicon-bonded hydrogen atomssuch as, for example, 5, 10, 20, 40, 70, 100, and more. Theorganohydrogensiloxane compounds suitable as Component (ii) can belinear, branched, cyclic, resins, and combinations thereof.

Component (ii) is exemplified by diorganohydrogensiloxy-terminatedpolyorganohydrogensiloxane polymers, diorganohydrogensiloxy-terminatedpolydiorganosiloxane-polyorganohydrogensiloxane copolymers,triorganosiloxy-terminatedpolydiorganosiloxane-polyorganohydrogensiloxane copolymers,triorganosiloxy-terminated polyorganohydrogensiloxane polymers, eachhaving a degree of polymerization of from 2 to 1,000, and preferablyfrom 5 to 100 and a viscosity at 25° C. of from 1 to 10,000millipascal-seconds, and preferably from 5 to 100 millipascal-seconds.The organo substituent on these siloxanes is exemplified by a monovalenthydrocarbon group having from 1 to 20 carbon atoms exemplified by alkylgroups such as methyl, ethyl, propyl, butyl, hexyl, octyl, and decyl,cycloaliphatic groups such as cyclohexyl, aryl groups such as phenyl,tolyl, and xylyl, and aralkyl groups such as benzyl and phenylethyl. Itis preferred that the organo substituent is methyl. The several organosubstituents can be identical or different, as desired.

Thus Component (ii) is preferably selected from the group consisting ofdimethylhydrogensiloxy-terminated polymethylhydrogensiloxane polymers,dimethylhydrogensiloxy-terminatedpolydimethylsiloxane-polymethylhydrogensiloxane copolymers,trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhydrogensiloxane copolymers, andtrimethylsiloxy-terminated polymethylhydrogensiloxane polymers, eachhaving a degree of polymerization of from 5 to 100 and a viscosity at25° C. of from 5 to 100 millipascal-seconds. Component (ii) can also bea combination of two or more of the above describedorganohydrogensiloxanes.

The amount of Components (i) and (ii) that is used in the compositionsof this invention, expressed in terms of the ratio of the number ofsilicon-bonded hydrogen atoms of Component (ii) to the number ofsilicon-bonded alkenyl groups of Component (i), should be sufficient toprovide a ratio of from 0.5:1 to 4.5:1, preferably a ratio of from 0.5:1to 3:1.

Component (iii) can be can be any platinum group mertal-containingcatalyst component. By platinum group it is meant herein ruthenium,rhodium, palladium, osmium, iridium and platinum and complexes thereof.Preferably Component (iii) is a platinum-containing catalyst. Theplatinum-containing catalyst can be platinum metal, platinum metaldeposited on a carrier such as silica gel or powdered charcoal, or acompound or complex of a platinum group metal. Preferredplatinum-containing catalysts include chloroplatinic acid, either inhexahydrate form or anhydrous form, and or a platinum-containingcatalyst which is obtained by a method comprising reactingchloroplatinic acid with an aliphatically unsaturated organosiliconcompound such as divinyltetramethyldisiloxane. Component (iii) ispresent in an amount sufficient to provide at least 10 weight parts,preferably 30 to 500 weight parts of platinum for every one millionweight parts of Components (i)+(ii), and it is highly preferred that itis present in an amount sufficient to provide 30 to 250 weight parts ofplatinum for every one million parts by weight of Components (i)+(ii).

Component (iv), the inhibitor, can be any material that is known to be,or can be, used to inhibit the catalytic activity of platinum groupmetal-containing catalysts. By the term “inhibitor” it is meant herein amaterial that retards the room temperature curing of a mixture ofComponents (i), (ii), and (iii), and any optional components withoutpreventing the elevated curing of the mixture. Examples of suitableinhibitors include ethylenically or aromatically unsaturated amides,acetylenic compounds, silylated acetylenic compounds, ethylenicallyunsaturated isocyanates, olefinic siloxanes, unsaturated hydrocarbondiesters, conjugated ene-ynes; hydroperoxides, nitriles, anddiaziridines.

Preferred inhibitors are exemplified by acetylenic alcohols exemplifiedby 1-ethynyl-1-cyclohexanol, 2-methyl-3-butyn-2-ol,2-phenyl-3-butyn-2-ol, 2-ethynyl-isopropanol, 2-ethynyl-butane-2-ol, and3,5-dimethyl-1-hexyn-3-ol, silylated acetylenic alcohol exemplified bytrimethyl(3,5-dimethyl-1-hexyn-3-oxy)silane,dimethyl-bis-(3-methyl-1-butyn-oxy)silane,methylvinylbis(3-methyl-1-butyn-3-oxy)silane, and((1,1-dimethyl-2-propynyl)oxy)trimethylsilane, unsaturated carboxylicesters exemplified by diallyl maleate, dimethyl maleate, diethylfumarate, diallyl fumarate, and bis-(methoxyisopropyl) maleate,conjugated ene-ynes exemplified by 2-isobutyl-1-butene-3-yne,3,5dimethyl-3-hexene-1-yne, 3-methyl-3-pentene-1-yne,3-methyl-3-hexene-1-yne, 1-ethynylcyclohexne, 3-ethyl-3-butene-1-yne,and 3-phenyl-3-butene-1-yne, vinylcyclosiloxanes such as1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, and a mixtureof a conjugated ene-yne as described above and a vinylcyclosiloxane asdescribed above.

The amount of inhibitor to be used in the solventless silicone coatingsof this invention is not critical. It is preferred that from 0.1 to 10parts by weight of inhibitor be used per 100 parts by weight ofcomponents (i)+(ii).

The solventless silicone coating compositions can further comprise (v) abath life extender compound in a total amount sufficient to furtherretard the curing reaction at room temperature. Examples of suitablebath life extender compounds include compounds which contain one or moreprimary or secondary alcohol groups, carboxylic acids (includingcompounds which yield carboxylic acids when exposed to water at roomtemperature), cyclic ethers, and water. Included in this group are theprimary and secondary alcohols; diols and triols, such as ethyleneglycol, propylene glycol and glycerine; partial ethers of diols andtriols, such as 2-methoxyethanol, 2-methoxypropanol, and2-methoxyisopropanol; tetrahydrofuran; water and aqueous solutions ofmineral acids, alkalis, and salts. Primary and secondary alcohols,preferably having fewer than 10 carbon atoms are the most preferred forthe compositions of this invention. Examples thereof include methanol,1-butanol, 2-butanol, tetradecanol and other alkanols, such as ethanol,and normal-, and iso-propanol, iso-butanol, and the normal-, secondary-,and iso-pentanols, -hexanols, -heptanols, and -octanols; benzyl alcohol,phenol, and other aromatic alcohols such as methylphenyl carbinol, and2-phenylethyl alcohol; allyl alcohol, and cyclohexanol. It is highlypreferred that the bath life extender is benzyl alcohol or water.

The amount of bath life extender (v) that is to be used can be as highas 10 parts or more by weight. Preferably, the amount of bath lifeextender to be used falls within the range of 0.01 to 5 parts, and mostpreferably 0.01 to 1 part by weight, per 100 weight parts of Components(i)+(ii).

The solventless silicone coating compositions of Component (A) canfurther comprise (vi) a release additive. Any of the well-known releaseadditives in the art may be employed. The release additive is preferablya siloxane resin consisting essentially of RSiO_(1/2) units andSiO_(4/2) units wherein R is independently an alkenyl group asdelineated hereinabove or an organo substituent and wherein the molarratio of RSiO_(1/2) units to SiO_(4/2) is from 0.6:1 to 4:1, preferablyfrom 0.6:1 to 1.9:1, and most preferably from 1.2:1 to 1.6:1. The organosubstituent on the siloxane resin is exemplified by a monovalenthydrocarbon group having from 1 to 20 carbon atoms exemplified by alkylgroups such as methyl, ethyl, propyl, butyl, hexyl, octyl, and decyl,cyclaliphatic groups such as cyclohexyl, aryl groups such as phenyl,tolyl, and xylyl, and aralkyl groups such as benzyl and phenylethyl. Itis preferred that the organo substituent is methyl. The several organosubstituents can be identical or different, as desired. The siloxaneresin can further be diluted with an organoalkenylsiloxane such as thosedescribed above (for example, vinyl or hexenyl containingpolydiorganosiloxane polymers or copolymers. The high release additivepreferably comprises 40 to 70 weight parts of the vinyl functional MQresin and 30 to 60 weight parts of the organoalkenylsiloxane polymer.From 1 to 99 weight parts of the high release additive may be employedin the solventless silicone release coating (A) of this invention, andpreferably 1 to 10 weight parts of high release additive is employed,per 100 weight parts of Components (i)+(ii).

The solventless silicone coating composition (A) can further compriseany optional components commonly used in platinum group metal catalyzedorganosilicon compositions, such as reinforcing and extending fillers,hydrocarbons and halohydrocarbons free of aliphatic unsaturation,colorants, stabilizers, adhesion modifiers, and adhesive-releasemodifiers.

Components (i)-(iv), and any optional components can be mixed togetherusing any suitable mixing means, such as a spatula, a drum roller, amechanical stirrer, a three roll mill, a sigma blade mixer, a breaddough mixer, and a two roll mill. The solventless silicone releasecoating of Component (A) can be prepared by homogeneously mixingComponents (i), (ii), (iii), (iv), and any optional components in anyorder. The order of mixing Components (i)-(iv) and any optionalcomponents is not critical however it is preferred that Component (iii),the platinum group metal-containing catalyst, be brought together in thepresence of Components (i), (ii), (iv), and any optional components. Itis highly preferred to mix Components (i), (ii), (iv), and any optionalcomponents in a preliminary mixing step followed by addition of catalyst(iii). Components (i)-(iv) and any optional components can be mixed atroom temperature (20-25° C.) or can be heated to temperatures above roomtemperature such as at temperatures of up to 200° C., however it ispreferred that if ingredients (i)-(iv) and any optional components areheated, they are heated to a temperature of from 50° C. to 120° C.

Component (A) can also be any of the radiation curable silicone coatingcompositions known in the art such as UV (ultraviolet) or EB (electronbeam) curable silicone coatings. These radiation curable siliconecoating composition generally comprise (i) an organosilicon compoundhaving at least two groups selected from the group consisting of epoxygroups, vinyl ether groups, acrylamide groups, and acrylate groups; and(ii) an initiator. Preferably the organosilicon compound (i) is selectedfrom the group consisting of epoxy-containing polyorganosiloxanes andepoxy-containing organopolysiloxanes.

The vinylether-containing organopolysiloxanes are exemplified bytrimethylsiloxy-terminatedpolydimethylsiloxane-polymethylvinylethersiloxane copolymers,vinyletherdimethylsiloxy-terminatedpolydimethylsiloxane-polymethylvinylethersiloxane copolymers,trimethylsiloxy-terminated polymethylvinylethersiloxane polymers, andvinyletherdimethylsiloxy-terminated polydimethylsiloxane polymerswherein the vinylether group is selected from the group consisting of—Q(OQ)_(c)OCH═CH₂ and —QSi(OQOCH═CH2)_(3−m)R_(m) wherein Q is analkylene group, C has a value of 0 to 10, m has a value of 0 to 2, and Ris a monovalent hydrocarbon group and wherein the vinylether-containingorganopolysiloxane has a degree of polymerization of from 3 to 700, andpreferably from 5 to 300 and a viscosity at 25° C. of from 5 to 25,000millipascal-seconds, and preferably from 5 to 1,500 millipascal-seconds.Component (i) in the radiation curable silicone coating can also be acombination of two or more of the above-described vinylether-containingorganopolysiloxanes. In the above formula, Q is independently analkylene group exemplified by methylene, ethylene, propylene, butylene,phenylene, trimethylene, 2-methyltrimethylene, pentamethylene,hexamethylene,3-ethylhexamethylene, octamethylene, decamethylene,dodecamethylene, tetradecamethylene, and octadecamethylene,cyclohexylene, phenylene, and benzylene, and R is exemplified by alkylgroups such as methyl, ethyl, propyl, butyl, hexyl, octyl, and decyl,cycloaliphatic groups such as cyclohexyl, aryl groups such as phenyl,tolyl, and xylyl, and aralkyl groups such as benzyl and phenylethyl.Preferably c and m have a value of 0.

The epoxy-containing organopolysiloxane can be any organopolysiloxanewhich contains at least two epoxy groups. The epoxy-containingorganopolysiloxanes are exemplified by trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylepoxysiloxane copolymers,epoxydimethylsiloxy-terminatedpolydimethylsiloxane-polymethylepoxysiloxane copolymers,trimethylsiloxy-terminated polymethylepoxysiloxane polymers, andepoxydimethylsiloxy-terminated polydimethylsiloxane polymers wherein theepoxy group is exemplified by 1,2-epoxyethyl, 2,3-epoxypropyl,3,4-epoxybutyl, 5,6-epoxyhexyl, 9,10-epoxydecyl, glycidoxymrethyl,alpha-glycidoxyethyl, beta-glycidoxyethyl, alpha-glycidoxypropyl,beta-glycidoxypropyl, gamma-glycidoxypropyl,2-(3,4-epoxycyclohexyl)ethyl, 3-(3,4-epoxycyclohexyl)propyl, and3,4-epoxycyclohexylbutyl wherein the epoxy-containing organopolysiloxanehas a degree of polymerization of from 3 to 700, and preferably from 5to 300 and a viscosity at 25° C. of from 5 to 25,000millipascal-seconds, and preferably from 5 to 1,500 millipascal-seconds.Component (i) in the radiation curable silicone coating can also be acombination of two or more of the above-described epoxy-containingorganopolysiloxanes.

It is preferred that from 95 to 99.5 weight percent of the radiationcurable organosilicon compound (i) be used in the radiation curablecoating compositions of the invention, and it is highly preferred thatfrom 97 to 99 weight percent of this compound be employed, said weightpercent being based on the total weight of the radiation curablesilicone coating composition.

Compounds suitable as the initiator (ii) include photoinitiators andsensitizers. Sensitizers have been described in great detail in the artin numerous publications and include materials such as the well-knownmaterial benzophenone. The photoinitiators are exemplified by oniumsalts, diaryliodonium salts of sulfonic acids, triarylsulfonium salts ofsulfonic acids, diaryliodonium salts of boronic acids, andtriarylsulfonium salts of boronic acids.

Preferred onium salts are bis-diaryl iodonium salts such as bis(dodecylphenyl) iodonium hexafluoroarsenate and bis(dodecylphenyl) iodoniumhexafluoroantimonate, and dialkylphenyl iodonium hexafluoroantimonate.

Preferred diaryliodonium salts of sulfonic acid are selected fromdiaryliodonium salts of perfluoroalkylsulfonic acids and diaryliodoniumsalts of aryl sulfonic acids. Preferred diaryliodonium salts ofperfluoroalkylsulfonic acids include diaryliodonium salts ofperfluorobutanesulfonic acid, diaryliodonium salts ofperfluoroethanesulfonic acid, diaryliodonium salts ofperfluoro-octanesulfonic acid, and diaryliodonium salts oftrifluoromethane sulfonic acid. Preferred diaryliodonium salts of arylsulfonic acids include diaryliodonium salts of para-toluene sulfonicacid, diaryliodonium salts of dodecylbenzene sulfonic acid,diaryliodonium salts of benzene sulfonic acid, and diaryliodonium saltsof 3nitrobenzene sulfonic acid.

Preferred triarylsulfonium salts of sulfonic acid are selected fromtriarylsulfonium salts of perfluoroalkylsulfonic acids ortriarylsulfonium salts of aryl sulfonic acids. Preferredtriarylsulfonium salts of perfluoroalkylsulfonic acids includetriarylsulfonium salts of perfluorobutanesulfonic acid, triarylsulfoniumsalts of perfluoroethanesulfonic acid, triarylsulfonium salts ofperfluoro-octanesulfonic acid, and triarylsulfonium salts oftrifluoromethane sulfonic acid. Preferred triarylsulfonium salts of arylsulfonic acids include triarylsulfonium salts of para-toluene sulfonicacid, triarylsulfonium salts of dodecylbenzene sulfonic acid,triarylsulfonium salts of benzene sulfonic acid, and triarylsulfoniumsalts of 3-nitrobenzene sulfonic acid.

Preferred diaryliodonium salts of boronic acids include diaryliodoniumsalts of perhaloarylboronic acids and preferred triarylsulfonium saltsof boronic acids are the triarylsulfonium salts of perhaloarylboronicacid.

The initiators (ii) may be present in any proportions which effectcuring in the compositions of this invention. Preferably the amount ofinitiator is from 0.1 to 10 weight percent based on the total weight ofthe composition, and it is highly preferred to use between 1 and 5weight percent based on the total weight of the radiation curablesilicone coating composition.

The radiation curable silicone coatings can further contain optionalingredients such as photosensitizers, fillers, high release additives,reactive diluents such as organic vinyl ethers, photochromic materials,dyes, colorants, preservatives, fragrances, and other radiation curablecompounds may be included in the composition. Preferably no more than 25parts by weight of the composition is occupied by optional ingredients.

Component (B) is a liquid silicone mist suppressant composition having aviscosity of from 150 to 50,000 millipascal-seconds (1 millipascalsecond=1 centipoise) obtained by a method comprising mixing: (a) atleast one organohydrogensilicon compound containing at least twosilicon-bonded hydrogen groups per molecule, (b) at least oneorganoalkenylsiloxane containing at least three silicon-bonded alkenylgroups per molecule, and (c) a platinum group metal-containing catalystwhich is present in an amount sufficient to provide 1 to 250 weightparts of platinum group metal per million weight parts of (a)+(b), withthe proviso that the ratio of the number of silicon-bonded hydrogenatoms of Component (a) to the number of silicon-bonded alkenyl groups ofComponent (b) is less than or equal to 1:4.6.

The organohydrogensilicon compound (a) is preferably free of aliphaticunsaturation and contains two or more silicon atoms linked by divalentradicals, an average of from one to two silicon-bonded monovalentradicals per silicon atom and an average of at least three or moresilicon-bonded hydrogen atoms per compound. The organohydrogensiliconcompound is preferably an organohydrogensiloxane containing an averageof three or more silicon-bonded hydrogen atoms such as, for example, 5,10, 20, 40, 70, 100, and more. The organohydrogensiloxane compoundssuitable as Component (a) can be linear, branched, cyclic, resins, andcombinations thereof.

Component (a) is exemplified by diorganohydrogensiloxy-terminatedpolyorganohydrogensiloxane polymers, diorganohydrogensiloxy-terminatedpolydiorganosiloxane-polyorganohydrogensiloxane copolymers,triorganosiloxy-terminatedpolydiorganosiloxane-polyorganohydrogensiloxane copolymers,triorganosiloxy-terminated polyorganohydrogensiloxane polymers, anddiorganohydrogensiloxy-terminated polydiorganosiloxane polymers, eachhaving a degree of polymerization of from 2 to 10,000, preferably from 2to 1,000 and a viscosity at 25° C. of from 0.5 to 500,000millipascal-seconds, and preferably from 0.5 to 10,000millipascal-seconds. The organo substituent on these siloxanes isexemplified by a monovalent hydrocarbon group having from 1 to 20 carbonatoms exemplified by alkyl groups such as methyl, ethyl, propyl, butyl,hexyl, octyl, and decyl, cycloaliphatic groups such as cyclohexyl, arylgroup such as phenyl, tolyl, and xylyl, and aralkyl groups such asbenzyl and phenylethyl. It is preferred that the organo substituent ismethyl. The several organo substituents can be identical or different,as desired.

Component (a) can also be dimethylhydrogensiloxy-terminatedpolymethylhydrogensiloxane-polymethyl(organo)siloxane copolymers,dimethylhydrogensiloxy-terminatedpolydimethylsiloxane-polymethylhydrogensiloxane-polymethyl(organo)siloxaneterpolymers, trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhydrogensiloxane-polymethyl(organo)siloxaneterpolymers, trimethylsiloxy-terminatedpolymethylhydrogensiloxane-polymethyl(organo)siloxane copolymers anddimethylhydrogensiloxy-terminated polymethyl(organo)siloxane copolymers,each having a degree of polymerization of from 2 to 10,000, preferablyfrom 2 to 1,000 and a viscosity at 25° C. of from 0.5 to 500,000millipascal-seconds, and preferably from 0.5 to 10,000millipascal-seconds. The “organo” substituention these siloxanes areexemplified by alkylaryl groups, polyoxyalkylene groups, epoxy groups,vinyl ether groups, acrylamide compounds, acrylate compounds, isocyanatecompounds, and alkyl groups having from 2 to 40 carbon atoms. Thealkylaryl groups are exemplified by styryl and alpha-methyl styryl. Thepolyoxyalkylene groups exemplified by polyoxyethylene groups,polyoxypropylene groups, polyoxyethylene-polyoxypropylene groups andpolyoxyethylene-polyoxybutylene groups. The alkyl groups are exemplifiedby ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, dodecyl,tetradecyl, hexadecyl, octadecyl, —C₂₀H₄₁, —C₂₂H₄₅, —C₂₄H₄₉, —C₂₆H₅₃,—C₂₈H₅₇, —C₃₀H₆₁, —C₃₂H₆₅, —C₃₄H₆₉, —C₃₆H₇₃, —C₃₈H₇₇, and —C₄₀H₈₁.

However, Component (a) is preferably selected from the group consistingof dimethylhydrogensiloxy-terminated polydimethylsiloxane polymers,dimethylhydrogensiloxy-terminated polymethylhydrogensiloxane polymers,dimethylhydrogensiloxy-terminatedpolydimethylsiloxane-polymethylhydrogensiloxane copolymers,trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhydrogensiloxane copolymers, andtrimethylsiloxy-terminated polyinethylhydrogensiloxane polymers, eachhaving a degree of polymerization of from 2 to 1,000 and a viscosity at25° C. of from 0.5 to 10,000 millipascal-seconds. Component (a) can alsobe a combination of two or more of the above describedorganohydrogensiloxanes.

The alkenyl groups of Component (b) are exemplified by vinyl, allyl,3-butenyl, 4-pentenyl, 5-hexenyl, 6-heptenyl, 7-octenyl, 8-nonenyl,9-decenyl, 10-undecenyl, 4,7-octadienyl, 5,8-nonadienyl, 5,9-decadienyl,6,11-dodecadienyl and 4,8-nonadienyl.

Component (b) is an organoalkenylsiloxane which is exemplified bytriorganosiloxy-terminatedpolydiorganosiloxane-polyorganoalkenylsiloxane copolymers,alkenyldiorganosiloxy-terminatedpolydiorganosiloxane-polyorganoalkenylsiloxane copolymers,triorganosiloxy-terminatedpolydiorganosiloxane-polyorganoalkenylsiloxane copolymers,alkenyldiorganosiloxy-terminatedpolydiorganosiloxane-polyorganoalkenylsiloxane copolymers, andtriorganosiloxy-terminated polyorganoalkenylsiloxane polymers, eachhaving a degree of polymerization of from 3 to 300, preferably 3 to 100,and a viscosity at 25° C. of from 1 to 1,000 millipascal-seconds, andpreferably from 1 to 200 millipascal-secorids. The organo substituent isas defined above including preferred embodiments thereof. The alkenylsubstituent is exemplified by vinyl, allyl, 3-butenyl, 4-pentenyl,5-hexenyl, cyclohexenyl, 6-heptenyl, 7-octenyl, 8-nonenyl, 9-decenyl,10-undecenyl, 4,7-octadienyl, 5,8-nonadienyl, 5,9-decadienyl,6,11-dodecadienyl, and 4,8-nonadienyl, with vinyl and 5-hexenyl beingpreferred.

Thus Component (b) is preferably selected from the group consisting oftrimethylsiloxy-terminated polymethylvinylsiloxane polymers,trimethylsiloxy-terminated polydimethylsiloxane-polymethylvinyisiloxanecopolymers, vinyldimethylsiloxy-terminatedpolydimethylsiloxane-polymethylvinylsiloxane copolymers,trimethylsiloxy-terminated polymethylvinylsiloxane polymers,trimethylsiloxy-terminated polymethylhexenylsiloxane polymers,trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhexenylsiloxane copolymers, andhexenyldimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhexenylsiloxane copolymers, cach having adegree of polymerization of from 3 to 100 and a viscosity at 25° C. offrom 1 to 200 millipascal-seconds. Component (B) can also be acombination of two or more of the above descyibed alkenyl siloxanes.

The amount of Components (a) and (b) that is used in the compositions ofthis invention, expressed in terms of the ratio of the number ofsilicon-bonded hydrogen atoms of Component (a) to the number ofsilicon-bonded alkenyl groups of Component (b), should be sufficient toprovide a ratio of less than or equal to 1:4.6, and preferably from1:4.6 to 1:500. The ratio of the number of silicon-bonded hydrogen atomsof Component (a) to the number of silicon-bonded alkenyl groups ofComponent (b) (i.e. SiH:SiVi ratio) depends on factors such as the type,amount, viscosity, and degree of polymerization of Component (a) and thetype, amount, viscosity, and degree of polymerization of Component (b).Some typical SiH:SiVi ratios include about 1:4.7 to about 1:5.5, andabout 1:6 to about 1:75. However, for the silicone mist suppressantcompositions of this invention, the SiH:Vi ratio is preferably from1:4.7 to 1:100.

Component (c) can be any platinum group metal-containing catalystcomponent. By platinum group it is meant herein ruthenium, rhodium,palladium, osmium, iridium and platinum and complexes thereof.Preferably Component (c) is a platinum-containing catalyst. Theplatinum-containing catalyst can be platinum metal, platinum metaldeposited on a carrier such as silica gel or powdered charcoal, or acompound or complex of a platinum group metal. Preferredplatinum-containing catalysts include chloroplatinic acid, either inhexahydrate form or anhydrous form, and or a platinum-containingcatalyst which is obtained by a method comprising reactingchloroplatinic acid with an aliphatically unsaturated organosiliconcompound such as divinyltetramethyldisiloxane. Preferably the catalyst(c) is added in an amount sufficient to provide 1 to 250 weight partsfor every one million weight parts of (a)+(b), and it is highly preferrdthat the amount is at 5 to 150 weight parts of platinum for every onemillion parts by weight of (a)+(b).

The method of obtaining the silicone mist suppressant composition canfurther comprise adding (d) an inhibitor during or after mixingcomponents (a), (b), and (c). Component (d), the inhibitor, can be anymaterial that is known to be, or can be, used to inhibit the catalyticactivity of platinum group metal-containing catalysts. By the term“inhibitor” it is meant herein a material that retards the roomtemperature curing of a mixture of Components (a), (b), and (c), and anyoptional component when incorporated therein in small amounts, such asless than 10 parts by weight of the composition, without preventing theelevated curing of the mixture. Examples of suitable inhibitors includeethylenically or aromatically unsaturated amides, acetylenic compounds,silylated acetylenic compounds, ethylenically unsaturated isocyanates,olefinic siloxanes, unsaturated hydrocarbon diesters, conjugatedene-ynes, hydroperoxides, nitrites, and diaziridines.

Preferred inhibitors are exemplified by acetylenic alcohols exemplifiedby 1-ethynyl-1-cyclohexanol, 2-methyl-3-butyn-2-ol,2-phenyl-3-butyn-2-ol, 2-ethynyl-isopropanol, 2-ethynyl-butane-2-ol, and3,5-dimethyl-I-hexyn-3-ol, silylated acetylenic alcohols exemplified bytrimethyl(3,5-dimethyl-1-hexyn-3-oxy)silane,dimethyl-bis-(3-methyl-1-butyn-oxy)silane,methylvinylbis(3-methyl-1-butyn-3-oxy)silane, and((1,1-dimethyl-2-propynyl)oxy)trimethylsilane, unsaturated carboxylicesters exemplified by diallyl maleate, dimethyl maleate, diethylfumarate, diallyl fumarate, and bis-(methoxyisopropyl) maleate,conjugated ene-ynes exemplified by 2-isobutyl-1-butene-3-yne,3,5-dimethyl-3-hexene-1-yne, 3-methyl-3-pentene-1-yne,3-methyl-3-hexene-1-yne, 1-ethynylcyclohexene, 3-ethyl-3-butene-1-yne,and 3-phenyl-3-butene-1-yne, vinylcyclosiloxanes such as1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, and a mixtureof a conjugated ene-yne as described above and a vinylcyclosiloxane asdescribed above.

The amount of inhibitor to be used in the silicone mist suppressantcompositions of this invention is not critical. It is preferred thatfrom 0.01 to 10 parts by weight of inhibitor be used per 100 parts byweight of component (a+b).

The ingredients and any optional ingredients can be mixed at anytemperature, however it is preferred that ingredients (a)-(c) and anyoptional ingredients are mixed at room temperature, or heated to atemperature of from 25° C. to 150° C.

Components (a)-(c), and any optional components can be mixed togetherusing any suitable mixing means, such as a spatula, a drum roller, amechanical stirrer, a three roll mill, a sigma blade mixer, a breaddough mixer, and a two roll mill. Components (a)-(c) can be prepared byhomogeneously mixing (a), (b), (c), and any optional components in anyorder. The order of mixing (a) to (c) and any optional components is notcritical however it is preferred that catalyst (c) be brought togetherin the presence of Components (a) and (b), and any optional components.It is highly preferred to mix Components (a) and (b) and any optionalcomponents in a preliminary mixing step followed by addition of catalyst(c). Mixing of Components (a), (b), and any optional compounds, andcatalyst (c) results in the formation of a reaction product.

The silicone mist suppressant composition, Component (B), is present inthe silicone coating composition in amount sufficient to reduce the mist(aerosol) of the coating during high-speed processes, which can readilybe determined by one skilled in the art through routine experimentation.It is preferably added to the solventless silicone coating compositionin an amount of 0.1 to 95 weight parts, and it is highly preferred thatthe silicone mist suppressant composition is added in an amount of 0.1to 10 weight parts, said weight parts being based on 100 weight parts ofthe solventless silicone coating composition.

Component (B), the silicone mist suppressant is a complex mixture ofhighly branched organoalkenylsiloxane polymers. A large excess ofComponent (b) is necessary to completely react the silicon-bondedhydrogen groups of Component (a) without reaching a gel point. Theproduct of this reaction is therefore different from silicone elastomerand gel compositions which react alkenyl siloxanes andorganohydrogensiloxane with the purpose of reaching a gel point. Thematerials of the present invention must remain as fluids and must notreach a gel point. Depending on the structure of the starting materials,the viscosity of the final product preferably is from 300 to 15,000millipascal-seconds.

In a second embodiment, this invention relates to a silicone coatingcomposition comprising (A) an organosilicon compound containing at leasttwo silicon-bonded alkenyl groups per molecule and (B) a liquid siliconemist suppressant composition having a viscosity of from 150 to 50,000millipascal-seconds(mPa·s) (1 millipascal-second=1 centipoise) obtainedby am method comprising mixing: (a) at least one organohydrogensiliconcompound containing at least two silicon-bonded hydrogen groups permolecule, (b) at least one organoalkenylsiloxane containing at leastthree silicon-bonded alkenyl groups per molecule, and (c) a platinumgroup metal-containing catalyst which is present in an amount sufficientto provide 1 to 250 weight parts of platinum group metal per millionweight parts of (a)+(b), with the proviso that the ratio of the numberof silicon-bonded hydrogen atoms of Component (a) to the number ofsilicon-bonded alkenyl groups of Component (b) is less than or equal to1:4.6. This silicone coating composition can optionally comprise (C) aninhibitor. The organosilicon compound of Component (A), the liquidsilicone mist suppressant of Component (B), and inhibitor (C) are asdescribed above including preferred embodiments thereof. The siliconemist suppressant composition is generally present in an amount of 0.1 to2,000 weight parts, and it is highly preferred that the silicone mistsuppressant composition is present in an amount of 0.1 to 10 weightparts, said weight parts being based on 100 weight parts of Component(A). The amount of inhibitor (C) to be used in the silicone coatingcompositions of this embodiment is preferably from 0.01 to 1 part byweight of inhibitor per 100 parts by weight of Components (A+B).

In a third embodiment, this invention relates to a method of reducingmist in a silicone coating composition comprising adding to asolventless silicone coating composition a liquid silicone mistsuppressant composition having a viscosity of from 150 to 50,000millipascal-seconds (1 millipascal second=1 centipoise) obtained by amethod comprising mixing: (a) at least one organohydrogensiliconcompound containing at least two silicon-bonded hydrogen groups permolecule, (b) at least one organoalkenylsiloxane containing at leastthree silicon-bonded alkenyl groups per molecule, and (c) a platinumgroup metal-containing catalyst which is present in an amount sufficientto provide 1 to 250 weight parts of platinum group metal per millionweight parts of (a)+(b), with the proviso that the ratio of the numberof silicon-bonded hydrogen atoms of Component (a) to the number ofsilicon-bonded alkenyl groups of Component (b) is less than or equal to1:4.6. The solventless silicone coating composition and the liquidsilicone mist suppressant composition are as described above includingpreferred embodiments and amounts thereof.

In a fourth embodiment, this invention relates to a method of making acured coating, the method comprising the steps of: (I) adding a liquidsilicone mist suppressant composition having a viscosity of from 150 to50,000 millipascal-seconds (1 millipascal second=1 centipoise) obtainedby a method comprising (I) mixing: (a) at least oneorganohydrogensilicon compound containing at least two silicon-bondedhydrogen groups per molecule, (b) at least one organoalkenylsiloxanecontaining at least three silicon-bonded alkenyl groups per molecule,and (c) a platinum group metal-containing catalyst which is present inan amount sufficient to provide 1 to 250 weight parts of platinum groupmetal per million weight parts of (a)+(b), with the proviso that theratio of the number of silicon-bonded hydrogen atoms of Component (a) tothe number of silicon-bonded alkenyl groups of Component (b) is lessthan or equal to 1:4.6 to a solventless silicone coating composition;(II) coating the mixture from (I) on the surface of a substrate; and(III) exposing the coating and the substrate to an energy sourceselected from the group consisting of (i) heat and (ii) actinicradiation in an amount sufficient to cure the coatings. This method canfurther comprise applying a pressure sensitive adhesive on the coatingafter step (III). The solventless silicone coating composition and theliquid silicone mist suppressant composition are as described aboveincluding preferred embodiments and amounts thereof.

By actinic radiation it is meant ultraviolet light; electron beamradiation; and alpha-, beta-, gamma- and x-rays. By heat it is meantinfrared radiation, hot air, microwave radiation, etc. Of course actinicradiation is frequently accompanied by heat and the use of a combinationof the two falls within the scope and spirit of the present method. Inthe preferred method of this invention, the coating process can beaccomplished by any suitable manner known in the art, such as byspreading, brushing, extruding, spraying, gravure, kiss-roll andair-knife.

In a preferred embodiment of the instant method the solid substrate is aflexible sheet material such as paper, polyolefin film andpolyolefin-coated paper or foil. Other suitable solid substrates thatcan be coated by the process of this invention include other cellulosicmaterials such as wood, cardboard and cotton; metallic materials such asaluminum, copper, steel and silver; siliceous materials such as glassand stone; and synthetic polymer materials such as polyolefins,polyamides, polyesters and polyacrylates. As to form the solid substratecan be substantially sheet-like, such as a peelable release liner forpressure sensitive adhesive; a fabric or a foil; or substantiallythree-dimensional in form.

After the silicone coating composition has been coated onto a substrateit is heated and/or irradiated with actinic radiation, as noted herein,to cure the liquid coating and to adhere it to the substrate.

In a preferred embodiment of the method of this invention, a flexiblesheet material, such as paper, metal foil or tapestock, is coated with athin coating of the silicone coating composition, preferably in acontinuous manner and the thus-coated material is then heated and/orirradiated to rapidly cure the coating, to provide a sheetlike materialbearing on at least one surface thereof an adhesive-releasing coating.The adhesive-releasing coating is subsequently brought into contact witha pressure sensitive adhesive, preferably in an in-line manner, to forman article having a peelable, i.e. releasable, adhesive/coatinginterface. Examples of such an article include, adhesive labels having apeelable backing, adhesive tape in roll form and adhesive packaged in astrippable container. The pressure sensitive adhesive can benon-silicone-based, such as the well-known acrylic or rubber types orsilicone-based, such as the peroxide- or platinum-curablepolydiorganosiloxane-based adhesives.

The method of this invention is also applicable to adhesive materials,other than pressure sensitive adhesives. Examples of said adhesivematerials include foods, graphite composites, asphalt and gum polymers.

The silicone mist suppressant compositions of this invention when addedto silicone coatings are effective in reducing the amount of mistgenerated by the release coating during high speed coating processessuch as for example when a silicone coating is coated onto a substratesuch as paper, and the coating is then subsequently cured onto thesubstrate using heat to provide a sheetlike material bearing on at leastone surface thereof an adhesive releasing coating.

The following examples are disclosed to further teach, but not limit,the invention, which is properly delineated by the appended claims. Allamounts (parts and percentages) are by weight unless otherwiseindicated.

The silicone mist particles produced by the “mist generator” describedhereinbelow were drawn, in some of the Examples, to a QCM CascadeImpactor (TM), (Model PC-2 Ten Stage QCM Cascade Impactor, CaliforniaMeasurements, Inc., Sierra Madre, Calif.) and analyzed. A completeanalysis of aerosol mass concentration and size distribution wasobtained from a sample of air taken for a short period of time (10seconds to 1 minute). Collected samples of the sized particles wereretained undisturbed (if the particles are solid) and were used directlyto obtain composition, size and shape (for solid particles only)information using auxiliary scanning electron microscopy (SEM) and otheranalytical techniques.

The instrument separates aerosol particles into 10 sizes from 0.05 to 25micrometers. It does this by drawing the aerosol-laden air samplethrough a series of 10 stages, each stage containing an inertialimpactor jet of decreasing size (various size of orifices) where theparticles are accelerated. Directly below each jet was a piezoelectricquartz crystal that was used as an impactor to collect the separatedparticles. As the jet of air exits from the nozzle it was forced to turnsharply to flow around the crystal. Larger particles in the stream,because of their inertia, continue to travel toward the crystal plateand impact on it. Smaller particles follow the flow of air around thecrystal to the next stage, which was a repeat of the proceeding stage,except it was equipped with smaller nozzle designed to impact smallerparticles. The 10 stages thus collect particles of smaller and smallersizes. Each crystal was the frequency-controlling element of aquartz-crystal microbalance (QCM), whose output frequency decreases whenparticles are collected on the surface. Placed in close proximity to thesensing crystal, but shielded from the collected particles, was anidentical reference crystal controlling the frequency of another circuitset about 2 kHz higher than that of the sensing crystal. The set ofcrystals in a stage were closely matched in frequency.

The beat frequency between the two oscillators was the signal indicativeof the mass collected. The particle size distribution was obtained bymonitoring the frequency change of QCM in each of the 10 stages.

A tip of stainless steel tube (¼′ in diameter) remoted from the QCMCascade Impactor (TM) was placed very closely to the nip point of themist generator. To start the measurement the Cascade Impactor wasinitialized by pushing the initialization button on the front panel ofthe control unit. The mist generator was set at a speed (either 1,000,1,500 or 2,000 ft/min) and allowed to run for 10 seconds before takingthe sample and then open the sampling knob of the Impactor for apredetermined period time (10 to 30 seconds). After sampling theImpactor was left to idle for additional 50 seconds to let the particlessettle in the stages. The amount of collected particles at each stagewas calculated by pushing the “final” button on the front panel. Theresult of the total amount of mist and particle size distribution isprinted out to both the CRT of the PC connected via the serial port andthe thermal printer on the controller. The data was taken from at leastaverage of three individual runs at a speed. When the individual datascattered too much two more measurements were made and then the twoextreme values (1 highest and 1 lowest) were discarded before theresults were averaged. diameter production scale forward roll coater theQCM cascade impactor was installed to measure the amount of mistproduced at 1,500 ft/min line speed. The tip of stainless steel tube (¼inch id.) for sample collection was located at 1 inch away from the nippoint of the applicator and nipping rollers of the coater. The coaterwas run for 10 seconds at 1,500 ft/min and then the mist sample wastaken for additional 10 seconds. Two to three data points were taken ata condition and then the average was taken as a result. The averagevariations were less than 15% of the mean values.

EXAMPLES 1-3

In Examples 1-3 hereinbelow, a methylhydrogensiloxane (A) and anorganoalkenylsiloxane (B) were thoroughly mixed at 25° C. Then, acatalyst (C) was added with thorough mixing at 25° C. The mixture wasthen brought to the desired reaction temperature and mixed at thattemperature for a time sufficient for the viscosity to stabilize(reaction A). Upon completion of the reaction, an inhibitor was added toinhibit the activity of the catalyst and stabilize the product. Table 1summarizes the reagents used, reaction conditions, and viscosity of thefinal products.

In Table 1 hereinbelow:

(A) denotes a trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhydrogensiloxane copolymer having a totalaverage degree of polymerization of about 24 with about 8 mol %methylhydrogen moiety on the siloxane chain and a viscosity of about 20millipascal-seconds.

(B-1) denotes a dimethylvinylsiloxy-terminatedpolydimethylsiloxane-polymethylvinyisiloxane copolymer having a totalaverage degree of polymerization of about 150 with about 2 mol %methylvinyl moiety on the siloxane chain and a viscosity of about 375millipascal-seconds.

(B-2) denotes a dimethylhexenylsiloxy-terminatedpolydimethylsiloxane-polymethylhexenylsiloxane copolymer having a totalaverage degree of polymerization of about 150 with about 2.7 mol %methylvinyl moiety on the siloxane chain and a viscosity of about 390millipascal-seconds.

(C) denotes a soluble platinum complex containing 0.67 wt. % platinum,formed from chloroplatinic acid and divinyltetramethyldisiloxane.

(D) denotes bis(2-methoxy-1-methylethyl) maleate.

Table 2 summarizes the mist-suppression performance of these materials.

(a) Coating line speed which corresponds to the rpm setting on the mistgenerator. The mist generator was a laboratory 2-roll coater capable ofrunning at a line speed over 2,000 feet/minute. The 2-roll coater wasequipped with two 6 inch diameter rollers (bottom roll: rubber coatedand top roll: chrome coated), two blades, one or each roll, and a bottompan for containing the liquid supply. The rubber coated bottom roll wasdriven by variable speed motor which can cover over 2,000 ft/min. ofline speed. The top roll was a nipping roll which is engaged with bottomroll by applying pressure. Since the measurement of mist is verysensitive to the environment the whole system was located in a hood andthe hood fan speed was kept low to minimize the influence of turbulenceof the hood to the measurement. A vacuum cleaner was attached to eachroll surface by using a coat hanger type accessory to sweep the mistaway once it passed the measuring point. The coating liquid was suppliedeither from the button pan or a dam on the top blade against the topmetal roller. The bottom pan feeding method was employed for all datareported herein. To obtain consistent results, the pressure settings oftop blade and top roller were kept at 10 and 50 psi, respectively andthe bottom blade was used as a doctoring blade to regulate the amount ofincoming fluid. The coater was made by Euclid Tool and Machines, BayCity, Mich.

(b) Measured using a Model 3225 Aerosizer DSP instrument, manufacturedby TSI Corporation. The Aerosizer instrument is capable of measuring thetotal number of mist particles and particle size distribution in asample of air drawn through the instrument at approximately 3 liters perminute for a set sample time. The sample time for all mist measurementsin this document was 30 seconds.

In the Examples, the silicone mist suppressant prepared above was addedto a silicone coating in the amount denoted in Table 2 below. Thesilicone coating was prepared by mixing the following ingredients: 95.5parts of a dimethylvinylsiloxy-terminated polydimethylsiloxane having anaverage degree of polymerization of about 130 and a viscosity of about300 millipascal-seconds, 4.5 parts of a trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhydrogensiloxane copolymer having a totalaverage degree of polymerization of about 40 with about 70 mol %methylhydrogen moiety on the siloxane chain; and 0.1 parts ofbis(2-methoxy-1-methylethyl) maleate.

(c) A control coating was run at the identical line speed and wasidentical to the silicone coating described above except it contained nosilicone mist suppressant.

TABLE 1 Wt. Parts Wt. Parts Wt. Parts Wt. Parts of and Type of SiH:SiViof Reaction of Final Viscosity Ex. # (A) (B) Ratio (C) Temp./Time (D)(mPa · s) 1 7.3 B-1 90.6 1:4.9 1.8 100° C./23 hrs 0.3 7930 2 6.6 B-192.5 1:5.5 0.6 100° C./23 hrs 0.3 5440 3 6.4 B-2 91.8 1:6.8 1.8 120°C./5 min 0 1860

TABLE 2 wt. % silicone mist suppressant in % mist particles (b) Ex. #Silicone Coating Line Speed (a) versus Control (c) 1 0.5% 2000 feet/min36% 2.0% 2000 feet/min 26% 5.0% 2000 feet/min 25% 10.0%  2000 feet/min19% 2 0.5% 2000 feet/min 35% 2.0% 2000 feet/min 27% 3 0.5% 2000 feet/min44%

What is claimed is:
 1. A silicone coating composition comprising: (A) asolventless silicone coating composition selected from compositionscomprising (A′)(i) an organosilicon compound containing at least twosilicon-bonded alkenyl groups per molecule, (ii) anorganohydrogensilicon compound containing at least two silicon-bondedhydrogen atoms per molecule, the ratio of the number of silicon-bondedhydrogen atoms of (ii) to the number of silicon-bonded alkenyl groups of(i) is from 0.5:1 to 4.5:1, (iii) a platinum group metal-containingcatalyst, and (iv) an inhibitor, or (A″)(I) an organosilicon compoundhaving at least two groups selected from the group consisting of epoxygroups, vinyl ether groups, acrylamide groups, and acrylate groups; and(II) an initiator; and (B) a liquid silicone mist suppressantcomposition having a viscosity of from 150 to 50,000 millipascal-seconds(mPa·s) (1 millipascal-second=1 centipoise) obtained by a methodcomprising mixing: (a) at least one organohydrogensilicon compoundcontaining at least two silicon-bonded hydrogen groups per molecule; (b)at least one organoalkenylsiloxane containing at least threesilicon-bonded alkenyl groups per molecule, and (c) a platinum groupmetal-containing catalyst which is present in an amount sufficient toprovide 1 to 250 weight parts of platinum group metal per million weightparts of (a)+(b), with the proviso that the ratio of the number ofsilicon-bonded hydrogen atoms of Component (a) to the number ofsilicon-bonded alkenyl groups of Component (b) is less than or equal to1:4.6.
 2. A composition according to claim 1, wherein the solventlesssilicone coating composition is selected from (A′).
 3. A compositionaccording to claim 1, wherein the solventless silicone coatingcomposition is selected from (A′), wherein (A′) is obtained by a methodcomprising mixing (i) an organosilicon compound containing at least twosilicon-bonded alkenyl groups per molecule; (ii) anorganohydrogensilicon compound containing at least two silicon-bondedhydrogen atoms per molecule, the ratio of the number of silicon-bondedhydrogen atoms of (ii) to the number of silicon-bonded alkenyl groups of(i) is from 0.5:1 to 4.5:1, (iii) a platinum group metal-containingcatalyst; and (iv) an inhibitor.
 4. A composition according to claim 2,wherein the ratio of the number of silicon-bonded hydrogen atoms of (ii)to the number of silicon-bonded alkenyl groups of (i) is from 0.5:1 to3:1.
 5. A composition according to claim 3, wherein the ratio of thenumber of silicon-bonded hydrogen atoms of (ii) to the number ofsilicon-bonded alkenyl groups of (i) is from 0.5:1 to 3:1.
 6. Acomposition according to claim 4, wherein (iii) is a platinum groupmetal-containing catalyst present in an amount sufficient to provide 30to 500 weight parts of platinum for every one million weight parts ofComponents (i)+(ii).
 7. A composition according to claim 4, wherein(iii) is a platinum group metal-containing catalyst present in an amountsufficient to provide 30 to 250 weight parts of platinum for every onemillion weight parts of Components (i)+(ii).
 8. A composition accordingto claim 5, wherein (iii) is a platinum group metal-containing catalystpresent in an amount sufficient to provide 30 to 500 weight parts ofplatinum for every one million weight parts of Components (i)+(ii).
 9. Acomposition according to claim 5, wherein (iii) is a platinum groupmetal-containing catalyst present in an amount sufficient to provide 30to 250 weight parts of platinum for every one million weight parts ofComponents (i)+(ii).
 10. A composition according to claim 3, wherein themethod further comprises heating the product obtained by mixingcomponents (i), (ii), (iii), and (iv) to a temperature of from 50° C. to120° C.
 11. A composition according to claim 1, wherein the ratio of thenumber of silicon-bonded hydrogen atoms of Component (a) to the numberof alkenyl groups of Component (b) is from 1:4.6 to 1:500.
 12. Acomposition according to claim 2, wherein the ratio of the number ofsilicon-bonded hydrogen atoms of Component (a) to the number of alkenylgroups of Component (b) is from 1:4.6 to 1:500.
 13. A compositionaccording to claim 3, wherein the ratio of the number of silicon-bondedhydrogen atoms of Component (a) to the number of alkenyl groups ofComponent (b) is from 1:4.6 to 1:500.
 14. A composition according toclaim 4, wherein the ratio of the number of silicon-bonded hydrogenatoms of Component (a) to the number of alkenyl groups of Component (b)is from 1:4.6 to 1:500.
 15. A composition according to claim 5, whereinthe ratio of the number of silicon-bonded hydrogen atoms of Component(a) to the number of alkenyl groups of Component (b) is from 1:4.6 to1:500.
 16. A composition according to claim 1, wherein (c) is a platinumgroup metal-containing catalyst present in an amount sufficient toprovide 5 to 150 weight parts of platinum for every one million weightparts of Components (a)+(b).
 17. A composition according to claim 6,wherein (c) is a platinum group metal-containing catalyst present in anamount sufficient to provide 5 to 150 weight parts of platinum for everyone million weight parts of Components (a)+(b).
 18. A compositionaccording to claim 7, wherein (c) is a platinum group metal-containingcatalyst present in an amount sufficient to provide 5 to 150 weightparts of platinum for every one million weight parts of Components(a)+(b).
 19. A composition according to claim 8, wherein (c) is aplatinum group metal-containing catalyst present in an amount sufficientto provide 5 to 150 weight parts of platinum for every one millionweight parts of Components (a)+(b).
 20. A composition according to claim9, wherein (c) is a platinum group metal-containing catalyst present inan amount sufficient to provide 5 to 150 weight parts of platinum forevery one million weight parts of Components (a)+(b).
 21. A compositionaccording to claim 1, wherein the method of obtaining the silicone mistsuppressant composition further comprises adding (d) an inhibitor aftermixing (a), (b), and (c).
 22. A composition according to claim 1,wherein the method of obtaining the silicone mist suppressantcomposition further comprises heating the product obtained by mixing(a), (b), and (c) to a temperature of from 25° C. to 150° C.
 23. Acomposition according to claim 21, wherein the method of obtaining thesilicone mist suppressant composition further comprises heating theproduct obtained by mixing (a), (b), and (c) to a temperature of from25° C. to 1 50° C and then adding (d) an inhibitor.
 24. A compositionaccording to claim 4, wherein (i) is selected from the group consistingof trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylvinylsiloxane copolymers,vinyldimethylsiloxy-terminatedpolydimethylsiloxane-polymethylvinylsiloxane copolymers,trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhexenylsiloxane copolymers,hexenyldimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhexenylsiloxane copolymers,trimethylsiloxy-terminated polymethylvinylsiloxane polymers,trimethylsiloxy-terminated polymethylhexenylsiloxane polymers,vinyldimethylsiloxy-terminated polydimethylsiloxane polymers, andhexenyldimethylsiloxy-terminated polydimethylsiloxane polymers, eachhaving a degree of polymerization of from 50 to 300 and a viscosity at25° C. of from 80 to 1,000 millipascal-seconds; and (ii) is selectedfrom the group consisting of dimethylhydrogensiloxy-terminatedpolymethylhydrogensiloxane polymers, dimethylhydrogensiloxy-terminatedpolydimethylsiloxane-polymethylhydrogensiloxane copolymers,trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhydrogensiloxane copolymers, andtrimethylsiloxy-terminated polymethylhydrogensiloxane polymers, eachhaving a degree of polymerization of from 5 to 100 and a viscosity at25° C. of from 5 to 100 millipascal-seconds.
 25. A composition accordingto claim 5, wherein (i) is selected from the group consisting oftrimethylsiloxy-terminated polydimethylsiloxane-polymethylvinylsiloxanecopolymers, vinyldimethylsiloxy-terminatedpolydimethylsiloxane-polymethylvinylsiloxane copolymers,trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhexenylsiloxane copolymers,hexenyldimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhexenylsiloxane copolymers,trimethylsiloxy-terminated polymethylvinylsiloxane polymers,trimethylsiloxy-terminated polymethylhexenylsiloxane polymers,vinyldimethylsiloxy-terminated polydimethylsiloxane polymers, andhexenyldimethylsiloxy-terminated polydimethylsiloxane polymers, eachhaving a degree of polymerization of from 50 to 300 and a viscosity at25° C. of from 80 to 1,000 millipascal-seconds; and (ii) is selectedfrom the group consisting of dimethylhydrogensiloxy-terminatedpolymethylhydrogensiloxane polymers, dimethylhydrogensiloxy-terminatedpolydimethylsiloxane-polymethylhydrogensiloxane copolymers,trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhydrogensiloxane copolymers, andtrimethylsiloxy-terminated polymethylhydrogensiloxane polymers, eachhaving a degree of polymerization of from 5 to 100 and a viscosity at25° C. of from 5 to 100 millipascal-seconds.
 26. A composition accordingto claim 6, wherein (iii) is chloroplantic acid or a platinum groupmetal-containing catalyst which is obtained by a method comprisingreacting chloroplatinic acid with divinyltetramethyldisiloxane.
 27. Acomposition according to claim 7, wherein (iii) is chloroplatinic acidor a platinum group metal-containing catalyst which is obtained by amethod comprising reacting chloroplatinic acid withdivinyltetramethyldisiloxane.
 28. A composition according to claim 8,wherein (iii) is chloroplatinic acid or a platinum groupmetal-containing catalyst which is obtained by a method comprisingreacting chloroplatinic acid with divinyltetramethyldisiloxane.
 29. Acomposition according to claim 9, wherein (iii) is chloroplatinic acidor a platinum group metal-containing catalyst which is obtained by amethod comprising reacting chloroplantinic acid withdivinyltetramethyldisiloxane.
 30. A composition according to claim 11,wherein (a) is selected from the group consisting ofdimethylhydrogensiloxy-terminated polydimethylsiloxane polymers,dimethylhydrogensiloxy-terminated polymethylhydrogensiloxane polymers,dimethylhydrogensiloxy-terminatedpolydimethylsiloxane-polymethylhydrogensiloxane copolymers,trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhydrogensiloxane copolymers, andtrimethylsiloxy-terminated polymethylhydrogensiloxane polymers, eachhaving a degree of polymerization of from 2 to 1,000 and a viscosity at25° C. of from 0.5 to 10,000 millipascal-seconds; and (b) is selectedfrom the group consisting of trimethylsiloxy-terminatedpolymethylvinylsiloxane polymers, trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylvinylsiloxane copolymers,vinyldimethylsiloxy-terminatedpolydimethylsiloxane-polymethylvinylsiloxane copolymers,trimethylsiloxy-terminated polymethylvinylsiloxane polymers,trimethylsiloxy-terminated polymethylhexenylsiloxane polymers,trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhexenylsiloxane copolymers, andhexenyldimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhexenylsiloxane copolymers, each having adegree of polymerization of from 3 to 100 and a viscosity at 25° C. offrom 1 to 200 millipascal-seconds.
 31. A composition according to claim12, wherein (a) is selected from the group consisting ofdimethylhydrogensiloxy-terminated polydimethylsiloxane polymers,dimethylhydrogensiloxy-terminated polymethylhydrogensiloxane polymers,dimethylhydrogensiloxy-terminatedpolydimethylsiloxane-polymethylhydrogensiloxane copolymers,trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhydrogensiloxane copolymers, andtrimethylsiloxy-terminated polymethylhydrogensiloxane polymers, eachhaving a degree of polymerization of from 2 to 1,000 and a viscosity at25° C. of from 0.5 to 10,000 millipascal-seconds; and (b) is selectedfrom the group consisting of trimethylsiloxy-terminatedpolymethylvinylsiloxane polymers, trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylvinylsiloxane copolymers,vinyldimethylsiloxy-terminatedpolydimethylsiloxane-polymethylvinylsiloxane copolymers,trimethylsiloxy-terminated polymethylvinylsiloxane polymers,trimethylsiloxy-terminated polymethylhexenylsiloxane polymers,trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhexenylsiloxane copolymers, andhexenyldimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhexenylsiloxane copolymers, each having adegree of polymerization of from 3 to 100 and a viscosity at 25° C. offrom 1 to 200 millipascal-seconds.
 32. A composition according to claim13, wherein (a) is selected from the group consisting ofdimethylhydrogensiloxy-terminated polydimethylsiloxane polymers,dimethylhydrogensiloxy-terminated polymethylhydrogensiloxane polymers,dimethylhydrogensiloxy-terminatedpolydimethylsiloxane-polymethylhydrogensiloxane copolymers,trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhydrogensiloxane copolymers, andtrimethylsiloxy-terminated polymethylhydrogensiloxane polymers, eachhaving a degree of polymerization of from 2 to 1,000 and a viscosity at25° C. of from 0.5 to 10,000 millipascal-seconds; and (b) is selectedfrom the group consisting of trimethylsiloxy-terminatedpolymethylvinylsiloxane polymers, trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylvinylsiloxane copolymers,vinyldimethylsiloxy-terminatedpolydimethylsiloxane-polymethylvinylsiloxane copolymers,trimethylsiloxy-terminated polymethylvinylsiloxane polymers,trimethylsiloxy-terminated polymethylhexenylsiloxane polymers,trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhexenylsiloxane copolymers, andhexenyldimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhexenylsiloxane copolymers, each having adegree of polymerization of from 3 to 100 and a viscosity at 25° C. offrom 1 to 200 millipascal-seconds.
 33. A composition according to claim14, wherein (a) is selected from the group consisting ofdimethylhydrogensiloxy-terminated polydimethylsiloxane polymers,dimethylhydrogensiloxy-terminated polymethylhydrogensiloxane polymers,dimethylhydrogensiloxy-terminatedpolydimethylsiloxane-polymethylhydrogensiloxane copolymers,trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhydrogensiloxane copolymers, andtrimethylsiloxy-terminated polymethylhydrogensiloxane polymers, eachhaving a degree of polymerization of from 2 to 1,000 and a viscosity at25° C. of from 0.5 to 10,000 millipascal-seconds; and (b) is selectedfrom the group consisting of trimethylsiloxy-terminatedpolymethylvinylsiloxane polymers, trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylvinylsiloxane copolymers,vinyldimethylsiloxy-terminatedpolydimethylsiloxane-polymethylvinylsiloxane copolymers,trimethylsiloxy-terminated polymethylvinylsiloxane polymers,trimethylsiloxy-terminated polymethylhexenylsiloxane polymers,trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhexenylsiloxane copolymers, andhexenyldimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhexenylsiloxane copolymers, each having adegree of polymerization of from 3 to 100 and a viscosity at 25° C. offrom 1 to 200 millipascal-seconds.
 34. A composition according to claim15, wherein (a) is selected from the group consisting ofdimethylhydrogensiloxy-terminated polydimethylsiloxane polymers,dimethylhydrogensiloxy-terminated polymethylhydrogensiloxane polymers,dimethylhydrogensiloxy-terminatedpolydimethylsiloxane-polymethylhydrogensiloxane copolymers,trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhydrogensiloxane copolymers, andtrimethylsiloxy-terminated polymethylhydrogensiloxane polymers, eachhaving a degree of polymerization of from 2 to 1,000 and a viscosity at25° C. of from 0.5 to 10,000 millipascal-seconds; and (b) is selectedfrom the group consisting of trimethylsiloxy-terminatedpolymethylvinylsiloxane polymers, trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylvinylsiloxane copolymers,vinyldimethylsiloxy-terminatedpolydimethylsiloxane-polymethylvinylsiloxane copolymers,trimethylsiloxy-terminated polymethylvinylsiloxane polymers,trimethylsiloxy-terminated polymethylhexenylsiloxane polymers,trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhexenylsiloxane copolymers, andhexenyldimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhexenylsiloxane copolymers, each having adegree of polymerization of from 3 to 100 and a viscosity at 25° C. offrom 1 to 200 millipascal-seconds.
 35. A composition according to claim16, wherein (a) is selected from the group consisting ofdimethylhydrogensiloxy-terminated polydimethylsiloxane polymers,dimethylhydrogensiloxy-terminated polymethylhydrogensiloxane polymers,dimethylhydrogensilox terminatedpolydimethylsiloxahe-polyinethylhydrogensiloxane copolymers,trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhydrogensiloxane copolymers, andtrimethylsiloxy-terminated polymethylhydrogensiloxane polymers, eachhaving a degree of polymerization of from 2 to 1,000 and a viscosity at25° C. of from 0.5 to 10,000 millipascal-seconds; and (b) is selectedfrom the group consisting of trimethylsiloxy-terminatedpolymethylvinylsiloxane polymers, trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylvinylsiloxane copolymers,vinyldimethylsiloxy-terminatedpolydimethylsiloxane-polymethylvinylsiloxane copolymers,trimethylsiloxy-terminated polymethylvinylsiloxane polymers,trimethylsiloxy-terminated polymethylhexenylsiloxane polymers,trimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhexenylsiloxane copolymers, andhexenyldimethylsiloxy-terminatedpolydimethylsiloxane-polymethylhexenylsiloxane copolymers, each having adegree of polymerization of from 3 to 100 and a viscosity at 25° C. offrom 1 to 200 millipascal-seconds.
 36. A composition according to claim17, wherein (c) is chloroplatinic acid or a platinum groupmetal-containing catalyst which is obtained by a method comprisingreacting chloroplatinic acid with divinyltetramethyldisiloxane.
 37. Acomposition according to claim 18, wherein (c) is chloroplatinic acid ora platinum group metal-containing catalyst which is obtained by a methodcomprising reacting chloroplatinic acid withdivinyltetramethyldisiloxane.
 38. A composition according to claim 19,wherein (c) is chloroplatinic acid or a platinum group metal-containingcatalyst which is obtained by a method comprising reactingchloroplatinic acid with divinyltetramethyldisiloxane.
 39. A compositionaccording to claim 20, wherein (c) is chloroplatinic acid or a platinumgroup metal-containing catalyst which is obtained by a method comprisingreacting chloroplatinic acid with divinyltetramethyldisiloxane.
 40. Acomposition according to claim 2, wherein (iv) is selected from thegroup consisting of 1-ethynyl-1-cyclohexanol, 2-methyl-3-butyn-2-ol,2-phenyl-3-butyn-2-ol, 3,5-dimethyl-1-hexyn-3-ol,trimethyl(3,5-dimethyl-1-hexyn-3-oxy)silane,dimethyl-bis-(3-methyl-1-butyn-oxy)silane,methylvinylbis(3-methyl-1-butyn-3-oxy)silane,((1,1-dimethyl-2-propynyl)oxy)trimethylsilane, diallyl maleate, dimethylmaleate, bis-(methoxyisopropyl) maleate, 2-isobutyl-1-butene-3-yne,3,5-dimethyl-3-hexene-1-yne, 3-methyl-3-pentene-1-yne,3-methyl-3-hexene-1-yne, 1-ethynylcyclohexene, 3-ethyl-3-butene-1-yne,3-phenyl-3-butene-1-yne,1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, and a mixtureof a conjugated ene-yne and a vinylcyclosiloxane.
 41. A compositionaccording to claim 3, wherein (iv) is selected from the group consistingof 1-ethynyl-1-cyclohexanol, 2-methyl-3-butyn-2-ol,2-phenyl-3-butyn-2-ol, 3,5-dimethyl-1-hexyn-3-ol,trimethyl(3,5-dimethyl-1-hexyn-3-oxy)silane,dimethyl-bis-(3-methyl-1-butyn-oxy)silane,methylvinylbis(3-methyl-1-butyn-3-oxy)silane,((1,1-dimethyl-2-propynyl)oxy)trimethylsilane, diallyl maleate, dimethylmaleate, bis-(methoxyisopropyl) maleate, 2-isobutyl-1-butene-3-yne,3,5-dimethyl-3-hexene-1-yne, 3-methyl-3-pentene-1-yne,3-methyl-3-hexene-1-yne, 1-ethynylcyclohexene, 3-ethyl-3-butene-1-yne,3-phenyl-3-butene-1-yne,1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, and a mixtureof a conjugated ene-yne and a vinylcyclosiloxane.
 42. A compositionaccording to claim 21, wherein (d) is selected from the group consistingof 1-ethynyl-1-cyclohexanol, 2-methyl-3-butyn-2-ol,2-phenyl-3-butyn-2-ol, 3,5-dimethyl-1-hexyn-3-ol,trimethyl(3,5dimethyl-1-hexyn-3-oxy)silane,dimethyl-bis-(3-methyl-1-butyn-oxy)silane,methylvinylbis(3-methyl-1-butyn-3-oxy)silane,((1,1-dimethyl-2-propynyl)oxy)trimethylsilane, diallyl maleate, dimethylmaleate, bis-(methoxyisopropyl) maleate, 2-isobutyl-1-butene-3-yne,3,5-dimethyl-3-hexene-1-yne, 3-methyl-3-pentene-1-yne,3-methyl-3-hexene-1-yne, 1-ethynylcyclohexene, 3-ethyl-3-butene-1-yne,3-phenyl-3-butene-1-yne,1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, and a mixtureof a conjugated ene-yne and a vinylcyclosiloxane.
 43. A silicone coatingcomposition comprising: (A) an organosilicon compound containing atleast two silicon-bonded alkenyl groups per molecule; and (B) a liquidsilicone mist suppressant composition having a viscosity of from 150 to50,000 millipascal-seconds(mPa·s) (1 millipascal-second=1 centipoise)obtained by a method comprising mixing: (a) at least oneorganohydrogensilicon compound containing at least two silicon-bondedhydrogen groups per molecule, (b) at least one organoalkenylsiloxanecontaining at least three silicon-bonded alkenyl groups per molecule,and (c) a platinum group metal-containing catalyst which is present inan amount sufficient to provide 1 to 250 weight parts of platinum groupmetal per million weight parts of (a)+(b), with the proviso that theratio of the number of silicon-bonded hydrogen atoms of Component (a) tothe number of silicon-bonded alkenyl groups of Component (b) is lessthan or equal to 1:4.6, and further provided that the organosiliconcompound used for Component (A) is different from theorganoalkenylsiloxane used for Component (B)(b).
 44. A compositionaccording to claim 43, wherein the composition further comprises (C) aninhibitor.
 45. A method of reducing mist in a silicone coatingcomposition comprising adding to a solventless silicone coatingcomposition a liquid silicone mist suppressant composition having aviscosity of from 150 to 50,000 millipascal-seconds (1 millipascalsecond=1 centipoise) obtained by a method comprising mixing: (a) atleast one organohydrogensilicon compound containing at least twosilicon-bonded-hydrogen-groups per molecule, (b) at least oneorganoalkenylsiloxane containing at least three silicon-bonded alkenylgroups per molecule, and (c) a platinum group metal-containing catalystwhich is present in an amount sufficient to provide 1 to 250 weightparts of platinum group metal per million weight parts of (a)+(b), withthe proviso that the ratio of the number of silicon-bonded hydrogenatoms of Component (a) to the number of silicon-bonded alkenyl groups ofComponent (b) is less than or equal to 1:4.6.